Elephant seals show one of the most extreme size differences between males and females in mammals. Large males compete ...

Not all fish play by the same reproductive rules. Evolutionary biology reveals how deception became a successful mating ...

Men have nipples, mammary glands and the hormones required, but the ability for male lactation rarely turns on. Here’s why ...

Why did our ancestors ditch the shell and start growing babies inside their bodies instead? In this episode of Big Ideas, ...

News footage these days sometimes shows wild horses crowding dry rangelands in the American West or deer wandering through ...

Evolutionary theory has revolutionized the way we understand humans – yet more than a century after Darwin's ideas reshaped biology, the female form of our species remains largely a mystery.

Most people know only two things about the appendix: You don’t need it – and if it bursts, you need surgery fast. That basic ...

Look around your home. A food wrapper, a shampoo bottle, a couch cushion and many other items very likely contain synthetic chemicals that were never tested for long-term safety before reaching store ...

When closely related species mate, their offspring sometimes survive but cannot reproduce. This pattern often affects males ...

Researchers discovered that selfish chromosomes exploit the Overdrive gene to destroy competing sperm during development, ...

Famous for stomping venomous snakes, the secretary bird has become a new climate early-warning system for the African grassland.